Racial and ethnic disparities in medication for opioid use disorder treatment among medicaid enrollees.

BACKGROUND: Racial and ethnic disparities in medications for opioid use disorder (MOUD) access exist, and more research is needed to understand the extent of national and cross-state variation in disparities in Medicaid, the largest payer for MOUD. METHODS: Using Medicaid claims (2017-2022) in 36 states, we conducted a repeated cross-sectional analysis to calculate opioid use disorder (OUD) occurrence and, among those with OUD, MOUD utilization, by enrollee race and ethnicity. Logistic regression models estimated the odds of MOUD receipt (any MOUD; buprenorphine; methadone; naltrexone) by enrollee race and ethnicity. Model 1 adjusted for age, sex, and study year, with year by race and ethnicity interactions; Model 2 additionally adjusted for state fixed effects; Model 3 additionally adjusted for Medicaid expansion status. MOUD receipt was also characterized at the state level. RESULTS: Compared to White enrollees, adjusted odds ratios (aOR) for receiving any MOUD among OUD-diagnosed enrollees were significantly lower for all other racial and ethnic groups across models. Fully-adjusted results found Black aOR= 0.50; 95% CI= 0.49-0.51; Asian or Pacific Islander aOR= 0.74; 95% CI= 0.70-0.79; Hispanic aOR= 0.92; 95% CI= 0.90-0.93. While MOUD rates grew by 16% per year overall, the time effect was negative for all minoritized racial and ethnic groups, implying worsening disparities. The ratio of treatment receipt comparing Black/White enrollees varied widely across states, ranging from.37 (MS) to.94 (LA). CONCLUSIONS: Results highlight the critical need to identify and address ongoing barriers to MOUD, particularly for minoritized groups, and for further research to understand and address state-level variation in these disparities.